This invention concerns television systems, and is particularly directed to a system in which a rear projection screen, storable in the system cabinet, is elevatable for viewing.
A system of this type is described and claimed in referent copending application Ser. No. 228,434. An ultra-compact, jack-in-the-box projection television receiver comprises cabinet means for enclosing components of the receiver and lid means hinged at the back of the cabinet. The receiver has vertically arranged, elevatable rear projection screen means selectively storable in the cabinet. Means are included for lifting the lid and elevating the screen from a first, receiver-inoperable position wherein the screen is stored in the cabinet and the receiver is substantially as compact as a conventional, large-screen console television receiver, to a second, elevated receiver-operable position wherein the screen is emerged from the cabinet. When the screen is in the second elevated receiver-operable position, the receiver is capable of displaying an image with an area greater than three times the image area on the conventional console television receiver.
An optical path for the projection television receiver described in the foregoing is disclosed in referent copending application Ser. No. 258,206. An image source means for forming a television image includes stationary image projection means permanently stored in the aforedescribed cabinet for projecting an aerial image of the television image along a path folded by optical path folding means onto the aforedescribed screen. The projection can take place when the screen is erected and located a predetermined image projection distance from the image source means. When the screen is elevated, the optical path is extended to a length equal to the predetermined image projection distance, and the projection image is coincident with the screen.
A screw-propelled mechanism known in the manufacturing art provides for lifting and lowering printed circuit boards between an upper electrical test station and a lower insertion/removal station. Means are provided for detecting the presence of boards at either station and reversing the direction of traverse.
The present invention provides for elevating the screen from a first receiver-inoperable position wherein the screen is lowered and stored in the cabinet and the receiver is ultra-compact, to an elevated receiver-operable position wherein the screen is emerged from the cabinet.